KR0149247B1 - The thermoplastic resin composition for polycarbonate & styrenic copolymer blends - Google Patents

Abstract

The thermoplastic resin composition of the present invention grafts a glycidyl methacrylate group on a polyethylene main chain and a first impact modifier of a core shell structure having a reactive group on a polycarbonate and a SAN and / or ABS resin blend, and graft copolymerizes the SAN group. The impact characteristics are improved by mixing the second impact stiffener.

Polycarbonate is a bisphenol A type aromatic polycarbonate having a weight average molecular weight in the range of 20,000 to 40,000.

In the core impact reinforcing material of the core shell structure, polymethyl methacrylate (PMMA) having a reactive functional group forms a shell, and rubber forms a core, and is used in the range of 5 to 25 parts by weight based on the total resin composition.

The second impact modifier has an epoxy functional group and is used in the range of 5 to 20 parts by weight based on the total resin composition.

Description

[Name of invention]

Thermoplastic resin composition consisting of a blend of polycarbonate and styrene copolymer

Detailed description of the invention

[Field of Invention]

The present invention relates to a thermoplastic resin composition composed of a blend of a polycarbonate resin and a styrenic copolymer.

More specifically, the present invention mixes polyacrylonitrile / butadiene / styrene (ABS) and / or polystyrene / acrylonitrile (SAN) resin to a polycarbonate resin, and the impact reinforcing material having a poly methyl methacrylate group in the blend. The present invention relates to a thermoplastic resin composition in which impact properties are improved by grafting a glycidyl methacrylate group to a polyethylene backbone and graft copolymerizing a polystyrene / acrylonitrile (SAN) group thereto.

[Background of invention]

Bisphenol A polycarbonate prepared by condensation of bisphenol A and phosgene is a polymer material having excellent transparency, impact resistance and heat resistance, and is widely used for injection molding, compression molding, sheet and film. However, the polycarbonate exhibits a great variation in scramble strength with varying thickness, vulnerability depending on the sharpness of the notch, weak impact strength at low temperatures, and inferior chemical resistance. To compensate for this, US Patent No. 3,239,582 discloses a resin blended ABS resin. The blend of polycarbonate and styrene copolymer resin is a mixture that improves the disadvantages such as low temperature impact resistance, arc resistance and thickness dependency along with the excellent properties of polycarbonate itself. These resins are used as injection resins for electric and electronic products and automotive interior materials. It is widely used.

Polycarbonate and styrene-based copolymer alloy (alloy) has the excellent properties as described above, but the blend itself is basically incompatibilities, the physical properties change depending on the processing conditions or specific conditions of use or the physical properties themselves are weak. A representative example of the drawback is a sharp drop in the impact strength at the weld line (weldline) of the injection molding, causing a problem that the impact strength is significantly reduced when used as a molding.

In order to solve this problem, a method of adding an impact modifier having a polymethyl methacrylate group to a blend of polycarbonate and ABS resin is used. The impact reinforcing material is present at the interface between the polycarbonate and the ABS resin, thereby improving the compatibility between the two resins, that is, the polycarbonate and the ABS resin.

As a film festival for the above purpose, various kinds have been developed to meet each purpose. As one of them, a compatibilizer having a core-shell structure in which a core is made of rubber and a shell is formed by grafting a acrylate group around the core is commercialized. .

In the core shell structure, the rubber component of the core improves the impact strength at low temperatures, and the shell portion acts as a compatibilizer at the interface between the polycarbonate and the ABS resin, thereby reducing the interfacial tension and reducing the indentation size of the dispersed phase. It is not good to improve the adhesion of Esau. The magnitude of the interfacial tension acting according to the shell component of the acrylic impact stiffener is also changed and the position of the impact stiffener is also changed. However, in the conventional impact stiffeners that are commercially available, almost all of the components are located at the interface, and the fluctuation is remarkably changed according to their positional variation.

Generally polycarbonate and ABS resins have been shown to have partial compatibility. And this compatibility is changed according to the content of acrylonitrile constituting the ABS resin, it is found that the content of acrylonitrile is the best compatibility in the composition of about 25% and these blends can exhibit good physical properties. lost.

On the other hand, polymethyl methacrylate (PMMA) has been found to be compatible with poly (styrene acrylonitrile) (SAN) resin in the range of the content of acrylonitrile in an amount. The location of impact modifiers in blends of polycarbonate SAN resins has a significant impact on physical properties. In general, when the impact reinforcing material is located at the interface is known to exhibit excellent physical properties and compatibility. However, it is known that in the case where the resin forming the dispersed phase exhibits brittle fracture, when the impact reinforcing material is placed in the dispersed phase, excellent physical properties may be exhibited. In this blend, the method of adjusting the position of the impact modifier is basically related to the interfacial properties of these two resins. If the content of acrylonitrile is 14% in the polystyrene / acrylonitrile (SAN) resin used as the dispersed phase, poly (methyl methacrylate) (PMMA) and poly (styreneacrylonitrile) (SAN) Therefore, the impact modifier is located in the poly (styreneacrylonitrile) (SAN) phase. When the acrylonitrile content is about 25%, polymethyl methacrylate (PMMA) and polystyrene acrylonitrile (SAN) are at the boundary of the commercial system, and the impact modifier is mainly located at the interface of these PC / ABS blends. Done. If the acrylonitrile content is more than 30% poly (styreneacrylonitrile) resin, the impact modifier is placed on the polycarbonate. Here, the blend of polycarbonate and poly (styrene atrylonitrile) (SAN) has the most compatibility at 25% of acrylonitrile, so this poly (styrene acrylonitrile) resin is mainly used with polycarbonate. Done. Therefore, it is necessary to envisage other mixing methods in order to control the position of the impact modifier in the range of this content. What can be considered in this way may be a method of changing the mixing order of the injected resin. That is, there may be a method of first mixing poly (styrene acrylonitrile) (SAN) and impact reinforcing material to make a blend and then mixing polycarbonate. In this case, of course, more impact modifiers are present than when mixed on poly (styreneacrylonitrile) (SAN). However, after various processes of injection and post-processing, they are continuously gathered at the interface as they were before and do not see a great effect. In addition, it requires more than two times of processing, resulting in a high cost. The present invention has been made to solve the above problems to make the majority of the impact stiffener is placed on the polystyrene / acrylonitrile (SAN), and also to be properly positioned at the interface to be designed to exhibit excellent physical properties.

As a method of improving the impact strength of polycarbonate and ABS resin blends, a method using polyglycidyl methacrylate is known from Japanese Patent Application Laid-Open No. 3-199255. This method relates to a process for producing low gloss products using copolymers having epoxy, methacrylate and styrene groups in this blend. Similar to the impact modifiers, there are impact modifiers in which the glycidyl methacrylate group is grafted on the main chain of polyethylene disclosed in Japanese Patent Publications JP 88-270713 and JP 88-312306, followed by graft copolymerization of SANRL. The impact reinforcing material has an epoxy group, and when used with an impact reinforcing material having a reactive group, the ABS resin or the SAN resin may be grafted so that the impact reinforcing material may be located inside the dispersed ABS or SAN resin. Using the above characteristics, the present inventors graft an impact modifier having a polymethyl methacrylate group and a polyethylene backbone glycidyl methacrylate group to a polycarbonate and a styrene-based copolymer, and then graft copolymerize the SAN group to the impact modifier. It is to develop a thermoplastic resin composition containing.

[Purpose of invention]

An object of the present invention is to graf a glycidyl methacrylate group to a polyethylene backbone and a first impact modifier of a core shell structure having a reactive group in a polybaconate and a SAN and / or ABS N-B blend, and graft copolymerization of SANRL. It is to provide a thermoplastic resin composition with improved impact characteristics by mixing the second impact modifier.

[Summary of invention]

The thermoplastic resin composition of the present invention grafts a glycidyl methacrylate group to a polyethylene main chain with a first impact modifier of a polyshell and a core shell structure having a reactive group in a SAN and / or ABS resin blend, and graft copolymerizes the SAN group. It is characterized in that the impact characteristics are improved by mixing the second impact stiffener.

The polycarbonate is preferably bisphenol A type aromatic polybaconate having a weight average molecular weight in the range of 20,000 to 40,000. In the core impact reinforcing material of the core shell structure, polymethyl methacrylate (PMMA) having a reactive functional group forms a shell and rubber forms a core, which is used in the range of 5 to 25 parts by weight based on the total resin composition.

The second impact modifier has an epoxy functional group and is used in the range of 5 to 20 parts by weight based on the total resin composition.

Detailed Description of the Invention

Polycarbonate resin is an aromatic bisphenol A polycarbonate commercially produced by condensation reaction between bisphenol A and phosgene.

Polycarbonate backbones are phenylene, biphenylene, naphthalene. It is preferable to contain an aromatic diol residue such as anthylene and the like. As the dihydric phenol, bis (hydroxy phenyl) acylidene and bisphenol A which are widely used, as well as substituted with halogen, alkyl, acyl and the like can be used. The polycarbonate is preferably an aromatic polycarbonate of bisphenol A type having a weight average molecular weight in the range of 20,000 to 40,000.

The ABS resin is obtained by grafting a cyan vinyl monomer and an aromatic vinyl monomer to rubber, and the SAN resin is a copolymer of an aromatic vinyl monomer and a cyan vinyl monomer. The rubbery polymer in the ABS resin is butadiene, isoprene, 1,3-heptadiene, methyl-1-3pentadiene, 2,3-3 dimethyl-1,3 jutadiene, isoprene, 2-ethyl-1,4-penta Butadiene substituted with dienes, chlorine and bromine and mixtures thereof, with preference being butadiene. Aromatic vinyl monomers include styrene, para methyl styrene, alpha methyl styrene, 4-N-propyl styrene, α-methyl vinyl roluene, halogen substituted styrene and mixtures thereof, with styrene and alpha methyl styrene being the best. Acrylonitrile, etaacrylonitrile, methacrylonitrile, allachloroacrylonitrile, beta chloroacrylonitrile and alpha bromonitrile, beta bromonitrile, etc. may be used as the cyanic vinyl monomer. Nitrile is the best. The molecular weight of SAN is preferably in the range of 100,000 to 300,00, and the content of acrylonitrile is preferably in the range of 15 to 30% by weight based on SAN. ABS has a butadiene content in the range of 40 to 60% by weight and has a graft copolymer of SAN graft copolymerized rubber. The content of the polycarbonate resin and the ABS and / or SAN resin in the resin composition of the present invention is in the range of 40 to 90% by weight of the polycarbonate resin and in the range of 60 to 5% by weight of the ABS and / or SAN resin. In the ABS resin, the butadiene content is in the range of 40 to 60% by weight, and the content of acrylonitrile / styrene is in the range of 60 to 40% by weight.

The core impact reinforcing material has a structure in which a shell portion composed of polymethyl methacrylate or butyl acrylate having a reactive functional group and a conjugated diene butadiene rubber-like aggregate form a core. Is used in the range of 5 to 25 parts by weight based on the total resin composition. The reactive functional group of the first impact modifier is the same as an acid group, and the functional group is preferably contained at 5% or less with respect to the total of the first impact modifier.

The second impact modifier having an epoxy functional group is a resin in which a glycidyl methacrylate group is grafted to a polyolefin main chain and SAN groups are graft copolymerized thereto. Examples of polymers grafted with glycidyl methacrylate groups to the polyolefin backbone include ethylene methacrylate glycidyl copolymer, ethylene vinyl acetate glycidyl copolymer, ethylene acrylic acid glycidyl copolymer and ethylene vinyl acetate glycidyl Copolymers. Of these, ethylene methacrylate glycidyl copolymer is preferred. The SAN group graft copolymerized in the second impact modifier is preferably in the range of 1 to 30% by weight based on the total of the second impact modifier. The second impact modifier is used in the range of 5 to 20 parts by weight based on the total resin composition.

The above polycarbonate, ABS and / or SAN resin, the first impact reinforcing material and the second impact reinforcing material are all mixed in a powder state and melt mixed in an extruder to prepare a resin composition according to the present invention.

The present invention is that the first impact modifier and the second impact modifier are mixed with polycarbonate, ABS and / or SAN resin, and the first and second impact modifiers react with the ABS and / or SAN. Located inside the impact modifier and the ABS and / or SAN resin, a portion of the first impact modifier has a morphology located at the interface of the blend of polycarbonate and ABS and / or SAN. Therefore, the resin composition according to the present invention is superior to the conventional resin composition in impact strength and elongation.

It can be understood in more detail by the following examples of the present invention, the following examples are merely for the purpose of illustrating the invention and are not intended to limit or limit the protection area of the present invention.

EXAMPLE

Polycarbonate, polystyrene / acrylonitrile (SAN), polyacrylonitrile / butadiene / styrene (ABS), the first impact modifier and the second impact modifier were mixed according to the contents shown in Table 1 according to Example 1-9 A resin composition was prepared.

Blends were made using a 40 mm diameter biaxial coaxial extruder from Berstorff, Germany. The processing temperature was set by operating the temperature of the extruder cylinder at 250-270 degreeC, and it operated with the screw speed of 200-400 RPM, and the discharge amount of 30-120 Kg / hour.

In the processing method, the basic resin and the first and second impact stiffeners were put together and extruded into pellets, and then injected and measured for physical properties. Injection molds were processed at an injection temperature of 250 ° C. with ASTM family molds. The / 4 notch impact strength shown in Example 1 was 24 Kg. Cm / cm and 1/8 for 67 Kg.cm/cm. Tensile strength was 652 Kg / cm 2 and elongation was 32% when tested at 50mm / min. If no polyacrylonitrile butadiene styrene resin was added, it is shown in Example 2. The elongation here is very good at 77%.

However, the value of 1/4 impact strength is about 13 to reveal brittle properties. This shows that the modification was almost similar to that of the original polycarbonate resin itself. In Example 3, when the polyacrylonitrile / butadiene / styrene (ABS) resin content is weighed by 15 parts by weight or more, the physical property change value can be seen. You can see that the 1/4 notch impact strength rises above 50. However, there is no continual improvement in elongation characteristics. In Examples 4 and 5, the physical property change when the first and second impact modifiers were used without using a polyacrylonitrile / butadiene / styrene (ABS) resin was shown. In Example 5, it can be seen that the 1/4 and 1/8 notch impact strengths are improved and the elongation characteristics are also very good, having a very good physical balance. On the other hand, in Example 4, the first and second impact stiffeners are used in half. It can be seen that the impact strength is further improved compared to Example 5, and the elongation characteristics are also shown to have a very good value of 100% or more. When 5 parts by weight of polyacrylonitrile / butadiene / styrene (ABS) resin is added thereto, the elongation is about 40% lower than that of Examples 4 and 5. It has excellent blend properties with 1/8 notch impact strength of 90 Kg.cm/cm or more. Physical properties when the content of the polycarbonate is more than 85% are shown in Examples 7,8 and 9. As shown in Examples 1 to 9, it is shown that a blend of very high 1/4 notch impact strength and elongation characteristics can be produced.

Simple modifications or changes of the present invention can be easily made by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (9)

Polycarbonate resins; ABS and / or SAN resins; A first impact reinforcing member of a core shell structure in which a shell portion composed of polymethyl acrylate or butyl acrylate having a reactive functional group and a conjugated diene butadiene rubbery polymer form a core portion; And a second impact reinforcing material having an epoxy functional group. The polycarbonate resin according to claim 1, wherein the polycarbonate resin is a bistenol-A aromatic polycarbonate having a weight average molecular weight in the range of 20,000 to 40,000. The method of claim 1, wherein the ABS resin is a butadiene content of 40 to 60% by weight of the thermoplastic resin composition, characterized in that the content of acrylonitrile / styrene is 60 to 40% by weight. The method of claim 1, wherein the content of the polycarbonate resin is in the range of 40 to 95% by weight, the content of the ABS and or SAN resin is a thermoplastic resin composition, characterized in that 60 to 5% by weight. The method of claim 1, wherein the reactive functional group of the first impact modifier is a thermoplastic resin composition, characterized in that less than 5% by weight relative to the first impact modifier. The method of claim 1, wherein the second impact modifier having an epoxy functional group is a thermoplastic resin composition, characterized in that the resin is graft copolymerized SAN resin to polyethylene glycidyl methyl methacrylate copolymer resin. The thermoplastic resin composition of claim 1, wherein the first impact modifier is used in an amount of 5 to 25% by weight based on the total resin composition. The thermoplastic resin composition of claim 1, wherein the second impact modifier is used in an amount of 5 to 20% by weight based on the total resin composition. 7. The thermoplastic resin composition of claim 6, wherein the SAN resin grafted to the second impact modifier is 1 to 30 weight 5 based on the second impact modifier.